Conventionally, a notebook computer (“notebook”) has at least one Video Graphics Array (VGA) port. In the past, a function key in combination with another key was used to toggle between the screen display of the notebook and a monitor coupled to a VGA port of the notebook. Thus, there was a way under software control invoked by user keystrokes to turn off the VGA port. However, in modern notebook computers, the VGA port is always on, and there is no way to turn-off the VGA port as there was in the past. Having the VGA port always on needlessly consumes power when the VGA port is not in use.
It should be understood that a VGA port uses analog RGB signals, as well as horizontal and vertical sync signals. It should further be understood that in contrast to a High-Definition Multimedia Interface (“HDMI”) port, a VGA port does not have a pin dedicated to auto-detection of a monitor plugged into such port.
Accordingly, it would be desirable and useful to provide an auto-detect feature for a VGA port absent a dedicated auto-detect pin to conserve power when such VGA port is not in use.